Inside a Family's Months-Long Quest to Find the Hit-and-Run Driver Who Killed Their Daughter

The last time Heidi Hanson talked to her daughter Grace Sulak, the 14-year-old varsity runner was heading back from a track meet with her best friend. Grace told her mom in a text that they were excited to stop at Which Wich, their favorite sandwich place, on the drive home.

She never made it: Before nightfall, Grace was killed in a hit-and-run that remains unsolved.

The driver who killed her — and severely injured her best friend, Emma, and Emma’s mom after sending their car careening head-on into a tree — has never been identified.

“I don’t know what kind of closure finding this person will give me,” Hanson tells PEOPLE. “It does not bring Grace back. But if it saves another life … If it saves another family from going through the indescribable pain of losing someone they love … that will be our closure.”

Authorities say the investigation continues, six months later — a quest for justice that started with a phone call:

“There’s been an accident.”

The Day of the Crash

On that Saturday in May, Grace and her best friend, Emma, took the bus nearly two hours from their hometown of Bluffton, South Carolina for a qualifying track meet in Columbia, South Carolina.

Hanson spoke to her daughter at noon and said Grace admitted that as much as she loved running, she was “ready for a little break.”

Courtesy Heidi Hanson

Courtesy Heidi Hanson

Like many teenagers at the end of a long school year, Grace was looking forward to her eighth-grade graduation — only two and a half weeks away — and vacation at her favorite summertime spot on Lake Lure in North Carolina.

It’s there where she could delight in jumping into the lake from the boathouse and finally take a break before cross-country started in July.

But a few minutes before 5:38 p.m., Emma’s mother, Andrea Dewey, saw a white Dodge Ram 2500 crew cab pickup truck coming up rapidly behind them on I-16. She quickly maneuvered out of the truck’s way, but the vehicle still hit them from behind — forcing them off the road and into a tree.

Grace was sitting in the back seat. She died instantly. Emma and her mother had to be air-lifted.

The driver of the pickup truck, though they must have seen the damage left behind them in their rearview mirror, never stopped.

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The first of any of this that Hanson heard was from her partner and Grace’s other mother, Kristen Sulak, who frantically called with news of an “accident.”

Hanson had a neighbor drive her to the scene, meanwhile calling all of the area hospitals looking for Grace. No one could tell her where her daughter had been taken — or that she was already gone.

When Hanson finally learned where she could find Emma and Andrea, she met up with Sulak at the hospital looking for updates. Instead, Hanson says, they were told “the highway patrol is coming to talk to us. And that’s never a good sign.”

Courtesy Heidi Hanson

Courtesy Heidi Hanson

‘Grace Was Always Kind’

Hanson says they made the decision right away to donate Grace’s eyes and heart valves. She says now, “Someone is going to get her heart valves and wonder, ‘Why the hell do I want to run every day? ‘ ”

Grace’s athleticism ran in her blood: Her family, including twin sister Faith Sulak, is very active, even running in an annual turkey trot.

“Grace was a very quiet, fierce competitor that led by example,” her cross-country coach, Dana House, tells PEOPLE. “I never heard her complain about anything except for her race performance every now and then. She was always striving to do better. She had a contagious smile and legs that just kept on growing.”

She and Faith were “like the sun and the moon,” Hanson says. “And best friends.”

“Grace was always kind, funny and annoying,” Faith says. “She always felt the need to be doing something active. And sadly, I am the complete opposite. I could read all day and be content, and she could run all day and be content.”

But that wasn’t enough for Grace, Faith says: “The activity would always have to include me, and [she’d] guilt trip me into doing something crazy.”

In the aftermath of the hit-and-run, Hanson says she was overwhelmed by the community’s response: About 2,000 people attended Grace’s memorial, and a local CrossFit group organized a fundraiser workout that raised $10,000 for both her family and the Dewey family. “Amazing Grace” T-shirts were made.

Grace was cremated in May, and her family spread her ashes in her favorite places on Lake Lure, near Chimney Rock in North Carolina. Faith says she found a special spot for her sister, with a “good view” of the lake.

Courtesy Heidi Hanson

Courtesy Heidi Hanson

‘This Person Should Not Be on the Road’

Though investigators have not identified the driver in the hit-and-run, here is what they do know:

“This vehicle that caused the collision was driving erratically, and struck the left rear of the other vehicle, causing it to go off the roadway,” Cpl. J.C. Francis with the South Carolina Highway Patrol tells PEOPLE.

Francis says “investigators continue to encourage the public to come forward with any information regarding this case.”

“All fatal collisions are tragic and take a tremendous toll on the family,” he says, “but when someone leaves the scene, it is especially hard on the family.”

Hanson says it’s not so much about punishing the driver as it is about getting them off the road. “Odds are he will be impaired and driving again,” she says. “He will end up in another accident.”

Sulak adds, “We need this person to come forward so we can move forward. Grace deserves justice, and this person should not be on the road to kill again.”

The Bluffton community, Grace’s school and her teammates still pay tribute to her memory: The Greenway Trail where Grace ran regularly during practice will now be adopted in Grace’s name; and the rec center soccer field where for years she played with Faith will be renamed in her honor.

Coach House has named the Bluffton High School Bobcat Scorcher, an annual 5K, “The Race for Grace” — and will continue to run it in Grace’s honor until 2020, her graduation date.

A memorial fund has also been established “which will enable us to continue her tradition of selfless giving,” Sulak says. “I do look forward to this as our family will be able to give back to the community that has given so much to us over the past six months.”

In September, for the first time, Faith had to celebrate her birthday without her twin sister.

“Now Thanksgiving is approaching,” Hanson says, “which is Grace’s favorite holiday because we have over 35 family and friends at our house for dinner. And family is what Grace was all about. There will definitely be a chair at the table for Grace.”